The present invention relates to a lamp ballasting approach wherein the regulating device is placed in a remote location with respect to the ballast and lamp assembly.
FIG. 1 depicts the equivalent circuit of a magnetically regulating lighting assembly 10 comprising a lamp 18, a ballast 14, and a regulating transformer 12 enclosed in a housing 16 which is typically used for H.I.D. (High intensity discharge) applications below the 1000 Watt level. These discharge lamps, below the 1000 Watt level, do not exhibit the overall performance desired for some lighting applications such as illumination of sports arenas, large industrial facilities and roadways where fixtures are elevated and/or spaced far apart. In such applications, a higher wattage lamp is desired. Such lamps, however, are not able to be ballasted in the manner shown in FIG. 1. The size and weight of the ballast limits its ability to fit within most ballast housings and would result in a heavy lighting assembly creating a moment arm about the support pole.
Another disadvantage of magnetically regualting ballasts is excessive heat loss. Such systems are not desirable in high temperature environments because of the undesirable amount of heat dissipated by the ballast 16. Accordingly, the size of the lamp (i.e. the wattage) is limited. There are applications, described below, wherein a higher wattage luminaire would be useful; however, such luminaires cannot be employed due to the significant heat loss of the ballast 16.
An object of the present invention is to provide a system and method for powering a lighting device where one unit, containing the ballast, is proximate to the first end of a support structure, and a second unit containing the regulating transformer is distal to the first end and proximate to the support structure.
Another object of the present invention is to provide a housing containing the regulating transformer which is connected to a power supply and to a remotely located second housing enclosing the lamp and ballast.
Still another object of the present invention is to provide a system that employs a second housing containing a ballast, an ignitor, and a capacitor that provides a low impedance path for the ignitor to prevent excessive attenuation to the ignitor pulse.